Advertisements
Advertisements
प्रश्न
Describe quantitative inheritance controlled by two pairs of genes.
उत्तर
- Quantitative inheritance is also known as polygenic inheritance in which characters are determined by two or more gene pairs which have additive or cumulative effect. These genes are called cumulative gene or polygenes.
- This quantitative inheritance can be explained by wheat kernel colour which is controlled by two pairs of genes Aa and Bb.
- H. Nilsson Ehle crossed red kernelled variety of wheat with white kernelled variety.
- Gene A and B determine the red colour of kernel (responsible for producing red pigment) and are dominant over their recessive allele a and b which do not produce red colour pigment and the expression is white, if dominant gene is not present. Thus, genotype of a parent with
red kernels is AABB and that of parent with white kernels is aabb. Genotype of F1 hybrids is AaBb. - Continuous variations in expressions is observed as each dominant gene produces specific amount of pigment and the shade of red colour, depends on number of dominant gene present
as shown in Punnett square. 
APPEARS IN
संबंधित प्रश्न
A geneticist interested in studying variations and patterns of inheritance in living beings prefers to choose organisms for experiments with shorter life cycle. Provide a reason.
In Mendel’s experiments, tall pea plants (T) are dominant over dwarf pea plants (t).
What is the phenotypic ratio and genotypic ratio of the above cross in (ii)?
Multiple Choice Question
Who among the following is called father of genetics?
When two genetic loci produce identical phenotypes in cis and trans position, they are considered to be ______.
If a round, green seeded pea plant (RRyy) is crossed with a wrinkled, yellow seeded pea plant (rrYY), the seeds produced in the F1 generation are ______.
Which is the one characteristic of the parents that can be inherited by their children?
Read the following and answer from given below:
Prashant wanted to find the genotype of a pea plant bearing purple coloured flowers in his kitchen garden. For this, he crossed purple-flowered plants with white-flowered plants. As a result, all plants which were produced had purple flowers only. Upon selfing these plants, 75 purple flower plants and 25 white flowers plants were produced. Now, he can determine the genotype of a purple-flowered plant by crossing it with a white-flowered plant.
Which of the following cannot be derived from the crosses done by Prashant?
Why did Mendel choose pea plant for his experiments?
Test Cross is a cross between:
State Mendel’s Law of Segregation.
